Attorne



Nov. 9 1926.

C. F. RICHIEY ET AL HEAT EXCHANGER Filed Feb 18. 1925 2 Sheets-Sheet 1 S 2 te M 0 E r I u a 2m c 1 Now- 9,1926. 0538? C; F. RICHEY ET AL HEAT EXCHANGER Filed Feb. 18. 1925 2 Sheets-Sheet 2 INVEN-TOR! CZar/es fizz/76y ma? BY 7&21/ gage.

Patented Nov. 9.1925.

UNITED STATES PATENT' OFFICE.

CHARLES F. RICHEY AND PAUL Y. DUFIEE, OF FRANKLIN, PENNSYLVANIA, AS-

SIG-NORS, BY MESNE ASSIGNMENTS, TO THE MOTOR FUEL CORPORATION, OF FRANKLIN, PENNSYLVANIA, CORPORATION OF PENNSYLVANIA.

HEAT EXCHANGER.

' Application filed February The present invention relates to the construction of a high pressure heat exchanger or pre-heater and more particularly to a pre-heater for use in oil cracking apparatus I in which it is necessary to handle oil at both very high temperatures and pressures. More particularly the present construction provides header mechanisms for the double tubes which are employed and particularly 10 means in such headers for connecting the tubes together without the necessity of employing packing rings or the like which rapidly deteriorate under the temperatures normally employed. At the same time, the

15 header constructions are such that allowance is made for the expansion and contraction of the tubes, the expansion of the inner tubes being different'from that of the outer tubes and being compensated for in the present 20 construction.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

25 The annexed drawing and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawing Fig. 1 is a vertical or side elevational view of the present construction showing one of the front headers and a rear header in sec- 35 tion;' Fig. 2 is a front elevational view of the device from the right of Fig. 1; Fig. 3 is a vertical sectional view on an enlarged scale of the front header construction, and Fig. 4 is a sectional view through the joint for the inner tubes in the rear header.

The present heat exchanger comprises a series of double pipes or tubes connected together to form two continuous chambers of which the inner chamber is adapted to carry the hot oil which is to be cooled and the'outer chamber to carry the cooler oil which is being heated. The connecting units or headers are so arranged that independent expansion of the outer and inner tubes is provided.

As best shown in Figs. 1 and 3, the front connecting unit or header consists of a hollow casting or forging 1 which is provided on its inner or left side as shown in Fig. 1

1a, 1925. Serial m. 9,990.

with two openings 2 which are counterbored or beveled off at their outer edges to form tube seats 3, these openings being connected together by an interior passage 4 within the header and being adapted for engagement with the outer tubes 5 of the heat exchanger. Extending through the front wall of the header are two openings or passageways 6, there being an internal ring or annular shoulder 7 extending down into the passageway and leaving the outer face of the opening beveled off to provide a seat 8 for the connecting U tubes 9 as best shown 111 Fig. 3. Each passageway interiorly of the ring is provided with a series of grooves 11 to receive the end of its inner tube which is expanded into such grooves as in boiler tube construction. In attaching the nner and outer tubes to the front header, 1t 1s seen that the outer tube 5 is provided at the header end with an enlarged head 12 which has its front surface beveled off as at 13 to fit against the counter-bored seat .3 of the header so as to form a leak proof joint therewith. This pipe 5 is held in place by means of a split washer 14 which fits snugly against the rear face 15 of the pipe end and this washer is pressed against the pipe by means of a heavy plate 16 which is secured to the header proper by means of bolts 17 which pass through apertures in the ring and have threaded engagement with tapped a ertures in the header. The inner tube 10 0 each pair of pipes has its forward end expanded into the grooves in such head-'- er to form a sealed joint. As will be seen from Fig. 1, the oil in the outer tube and surrounding the inner tube passes from one outer tube to another through the interior passageway of the header.

To connect the inner tubes of one series to another, a U tube 9 is employed which has its ends 20 headed or bulged so as to fit the counter-bored seats on the outside of the header as best shown in Fig. 3 and these bulged ends-20 are securely held in place by means of split washers 21 which fit the back side 22 of the bulge and which are forced tightly thereagainst by means of plates or flanges 23 which are shouldered as at 24'so as to receive the s lit washers 21 and which are secured to t e headers by means of bolts 25 passing through suitable against the curved portion 51 of the apertures in the flanges and having threaded engagement with tapped apertures in the header.

The inlet and outlet ends of the header are formed similarly to the headers just described except that an inlet pipe connecting flange 27 corresponding in construction to one of the U tubes is connected at the side 28 of the header to connect with the interior header passage, the inner tube of the header being connected through a similar flange with the interior inlet or outlet pipe 29 of the heat exchanger. It will be noticed that the front ends of both the inner and the outer tubes are thus held in fixed relation with each other and the expansion of the pipesis compensated for in the rear-headers which will be described in detail.

Each rear header consists of a hollow casting 30 having a forward heavy base 31 and a hollow semicircular rearwardly extending wall 32 forming an interior passageway 33 which is open at its forward ends through apertures 34 in the base of. the

header. The outer tubes 5 are mounted in this header in the same manner as they are mounted in the front header, the tubes having headed ends 35 and the holes 34 in the header being beveled off as at 36 so as to receive the beveled edge 37 of the pipe end and being secured in place by meansof split washers 38 and rings or plates 39 which are held to the header by means of the bolts 40.-

The connection for the inner tubes is a floating one, the rear ends 50 of the main inner tubes 10 being reduced in size as they approach the header'and then being thickened as at 42 and provided with a beveled front face 43 and screw threads 44 upon the exterior. The outside. diameter of the screw threads being approximately that of the normal outside diameter of the inner tube 5 ahead of its reduced portion. The connectors for the inner tubes are U shape pieces45 of pipe having headed or bulged ends 46 which are formed with a square shoulder 47 at the rear of the bulge. ,The front portion 47 of the bulge is beveled off and also curved so as to form a line contact with the beveled face of the inner tube. These U sha ed pipes 45 are securely held to the inner tube which have a forward shoulder 49 fitting against the shoulder of the pipe end and being provided rearwardly with an enlarged.

portion 51 having a curved or spherical surface 52. A locking union 53 is employed which is hollow and provided at the rear with a ball seat 54 adapted to snugly fit washer, the forward interior portion of the union being screw threaded as at 55 so as to mner tube to force the meeting. edges of the s by means of split washers 48 split.

engage with the threads on the end of the two pipes tightly together.- This provides a perfect balljoint which can compensate for the movement of the tubes due to temperature variations. In this manner, the inner tubes are connected together and are loosely mounted through the rear headers so that they may move longitudinally, independently of the outer tubes and the headers, the hollow portions of the header being large enough to allow for this independent movement due to unequal expansion of the two pipes.

The present heat exchanger as before stated, is adapted for use in oil cracking apparatus where the oil pressures in the two ,tubes are substantially the same and thus the tendency for oil to leak from one tube to the other at the'joints is'eliminated as the pressures on the two oil lines remain substantially equal at all times. construction allows the outer set of tubes to be readily removed for replacement or cleaning, it being only necessary to remove the bolts which hold the rings or flanges from the headers to remove the outer tubes. The inner tubes may then be readily cleaned as both ends are opened by the removal of the header rings. It is of course to be understood that the hot oil flows through the mner tubes of the exchanger and as this oil is at suflicient temperature to heat the tubes to a condition where their strength is somewhat reduced, it is advisable to encase these tubes in other tubes which carry a quantity of relative cool oil which is at the same pressure as the oil in the inner tubes so that the inner tubes are relieved of the burden of carrying the pressure of the hot oil. At thesame time, this heat is sufiicient to cause a relatively great expansion of the inner tubes as compared to the expansion of the outer tubes and thus this unequal expansion must be compensated for in some manner and this has been done in the present construction by allowing the inner tubes to float through the rear headers independently of the movement of the outer tubes. The joint construction employed does away with the necessity of using packing washers, the meeting surfaces being all metal and so formed that leak proof joints may be readily agtained by tightening the locking rings or ates.

p Other modes of applying the of our invention may be employe instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

(principle We therefore particularly point out and distinctly claim as our invention 1. In tube fastening meansior heat ex changers, the combination of two tubes having enlarged headed ends, a header com- The present prising a hollow casing having in its rear wall two apertures having cone-shaped seats for engagement with said tube ends, two inner pipes extending through said pipes and secured in the front wall of said header casing, said casing having two apertures in its'front wall for the reception of said inner pipes, said apertures being formed on the front face of said front wall with coneshaped seats, a U-tube having headed ends adapted to fit said last named cone-shaped seats, and means for securingall of said headed tube ends in said seats comprising a split washer for each tube adapted to fit behind the headed end, a ring mounted "on each tube end and having a shoulder adapted to fit around and against said washer, and bolts passing through each ring and engaging in said casing to force said washer against said tube end to seat the latter in its casing seat.

2. In tube fastening means for heat ex changers, the combination of two tubes having enlarged headed ends, a header comprising ahollow casing having in its rear wall two apertures having cone-shaped seats for engagement with said tube ends, two inner pipes extending through said pipes, said casing being provided in its forward Wall with apertures-for the reception of the ends of said inner tube, said apertures being grooved adjacent the interior face of said front wall, said ends of said inner tubes being expanded into said grooves, said forward wall apertures being formed on the front face with cone-shaped seats, a U-tube having headed ends adapted to fit headed end, a ring mounted on each tube end and having a shoulder adapted to fit around and against said washer, and bolts passing through each ring and engaging in said casing to force said washer against said tube end to seat the latter in its casing seat.

3. In a heat exchanger, the combination of a rear header comprising a base having a hollow body portion and two apertures communicating with said hollow body and provided with cone shaped seats, two pipes having headed ends adapted to fit in said seats and two inner pipes mounted within said first named pipes and provided with thickened threaded ends having interior cone shaped seats, a U tube having headed ends adapted to fit into the cone shaped seats in said inner pipe ends and means for securing said U tube to said inner pipes consisting of a split washer mounted on each end of said U tube against the head and a union for each joint comprising a cylinder having exteriorly placed threads at one end for engagement with said threaded pipe ends and a bearing seat at the other end-adapted to fit said split washer to draw the same tightly against the head of said U tube to force the head into seating position in its inner pipe seat.

Signed by us this 4" day of February,

CHARLES F. RICHEY. PAUL Y. DUFFEE. 

